<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>SayHello</title>
    <script type="text/javascript" src="../script/jquery-1.7.2.js"></script>
    <script type="text/javascript">
        /*window.onload = function () {
            var btn01 = document.getElementById("btn01");
            btn01.onclick=function () {
                console.log("btn01的单击事件");
            }
        }*/
        console.log($);
        $(function () {
            let $btn01 = $("#btn01");
            $btn01.click(function () {
                console.log("btn01的单击事件");
            });
        });
    </script>
</head>
<body>
    <button id="btn01">SayHello</button>
</body>
</html>